The motive could also be Political, due to trade relationships with Srivijaya samraajyam of Kadaaram. Sri Vijaya, had been very poewrful to control trade on South East Asian belt, the then busiest part of the world.
RRC, had given a way for Choodamanivarman to construct the Viharams.
Later, Sangraama Vijayothunga Varman, might have triggered comething that would have caused the Great Rajendhra to finish them off.